Hydraulic governor



March 6, 1934 L. A. DUMSER ET AL 1,949,711

HYDRAULIC GOVERNOR Filed July 2l, 1931 Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE HYDRAULIC GOVERNOR Application July 21, 1931, Serial No. 552,207

13 Claims.

This invention relates generally to hydraulic governors and more particularly to a feed control device for movable supports.

This application is a continuation in part of our copending application Serial No. 339,618, led February 13, 1929. In that application we have disclosed one form of the invention embodied in a milling machine for the purpose of controlling the feed to depth of a rotary cutting tool, which tool is mounted on a support reciprocated by a pressure fluid operated piston and cylinder device.

The general object of the invention is to provide a new and improved hydraulic governor which is simple in construction and emcient in operation, and which may be readily installed and arranged to control the speed of the movement imparted to a tool or work support by the actuating means therefor.

Another object is to provide such a device of new and improved construction embodying an adjustable control valve for adjusting the speed of movement.

Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawing, in which:

Fig. 1 is a vertical central section taken through a preferred form of the invention.

Fig. 2 is approximately a vertical central section taken through a modified form ofthe invention.

Fig. 3 is a transverse section substantially along the line 3-3 of Fig. 2.

Fig. 4 is an enlarged fragmentary section showing a detail of construction.

Fig. 5 .is a view substantially along the line 5-5 of Fig. 4.

For purposes of disclosure we have illustrated in the drawing and shall hereinafter describe in detail a preferred embodiment of the invention, together with a modified form thereof, with the understanding that we do not intend to limit the invention to the particular constructions and arrangements shown, it being contemplated that various changes may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

In the form illustrated in Fig. 1, the invention is disclosed as comprising a cylinder 15 having a plunger or piston 16 slidably mounted therein and normally projecting out through the open upper end of the cylinder. Resilient means such as an expansive coiled spring 17 positioned in a recess in the bottom of the cylinder 15 and (Cl. 18S-94) engaging the lower end of the piston 16 is arranged to move the piston outwardly, the piston being retained in the cylinder and held against rotary movement by means of a screw device 18 extending through the Wall of the cylinder and 00 two bores 22 and 23 are formed to provide inde- 65 pendent connecting passages between the reservoir 20 and the cylinder 15. An enlarged portion 24 of the bore 22 serves to contain a spring pressed ball check valve 25 arranged to prevent passage of fluid through that bore from the cylinder, and a needle valve 26 in an enlarged portion of the bore 23 and operable by a handle 27 controls the rate of flow through that bore. A

by-pass 28 is provided around the stem of the valve 26 to permit free passage for the liquid 75 from the valve orifice to the reservoir.

The reservoir 20 is adapted to contain a fluid, preferably oil, which will normally tend to pass through the bore 22 past the check valve 25 to fill the cylinder 15 when the piston 1'6 is movedl 80 outwardly of the cylinder. When the piston 16 is moved inwardly of the cylinder, the fluid beneath the piston cannot be forced out of the cylinder through the bore 22 because ofthe valve 25 and the speed at which the piston 16 85 may be moved will therefore be determined by the pressure applied by theactuating device and the adjustment of the needle valve 26 which governs the size of the only available outlet.

In the form illustrated in Figs. 2 to 5, a cylinder 90 30 and reservoir 31 are cast integrally and provided with a. cover piate'sz.. A piston 33 is sudably mounted in the cylinder `30 and has a portion or stem 34 of reduced diameter which extends outwardly through a bore 35 in the cover 95 plate 32. Preferably a guard device 36 is secured to the upper end of the stem 34 so as to prevent foreign matter from collecting on the stem. In this 'form of the invention a pair of coiled springs 37 are positioned in recesses 38 in the lower end of the cylinder and act as -a resilient means for returning the piston to its upper or outward position. Pins 39 secured to the piston extend into said springs in order to keep them in alinement.

The reservoir 31 is adapted to contain oil or other fluid and is arranged to supply such iiuid to the lower end of the cylinder 30.4 Aslllustrated in the drawing, a iib 40 extends along the bottom of the reservoir 31 and has a longitudinally extending passage 41 formed therein which communicates at one end with the lower end of the cylinder 30. Intermediate its ends the passage 41 is arranged to be supplied with fluid from the reservoir by means of a port 42 extendingtransversely through the rib 40 and a vertical port 43. A ball type check valve 44 is arranged to permit the ilow of fluid from the port 43 to the passage 41 and to prevent flow of fluid in a reverse direction. As illustrated most clearly in Fig. 2, the valve 44 ls positioned in an annular recess 45 and is prevented from escaping by means of a screw plug 46.

Fluid from the lower end of the cylinder 30, when the piston 33 is moved downwardly, is arranged to flow into the reservoir 31 through the passage 41 and an adjustable outlet passage intermediate said passage and the reservoir. As illustrated in the drawing, a short vertical port 47 communicates at one end with the passage 41 and at its other end with a bore 48 of a ring 49. This ring is positioned in a recess 50 in the rib 40 and is secured in position by means of a tubular member 51 positioned intermediate said ring and a threaded sleeve 52 supported in the cover plate 32. A side wallport 57 is provided in this tubular member so as to complete the passage to the reservoir 31. A cylindrical valve 53 -ls positioned in the bore 48 of the ring 49 and is secured to the lower end of a stem 58 which extends upwardly through the tube 51 and sleeve 52, and has a manually operable knob 54 on its upper end. The valve 53 is provided with a tapered longitudinally extending groove 55 arcuate in cross section, which serves as a valve port for controlling the rate of flow of the fluid from the cylinder 30 back to the reservoir 31. It will be apparent that the portion 56 of the groove 55 at the upper end of the ring 49 cooperates with the bore 48 of the ring to define the restricted portion of the discharge passage. The stem 58 is preferably provided with a screw threaded portion engaging a thread in the sleeve 51 to facilitate adjustment of the valve.

As illustrated in Figs. 2 and 3, a passage 59 is preferably provided intermediate the upper end of the cylinder 30 and the upper end of the reservoir 31, so as to allow the upper portion of the cylinder to be exhausted during the upward movement of the piston\33. The cover plate 32 is provided with a suitable vented plug 60 which may be removed for the purpose of filling the reservoir. In order to gage the height of the oil in the reservoir, an overflow valve 61 is mounted on the side wall of the reservoir at the desired level, and may be opened during the filling operation.

Although both forms of the invention illustrated in the drawing disclose piston and cylinder devices in which the pistons are arranged to move vertically, the invention is not to be construed as limited to such an arrangement since the relative positions of the cylinder and fluid reservoir may be readily modified by those skilled in the art. It will be evident that by mounting the invention on the machine so that the extending portion of the piston is positioned in the path of a movable support the device will operate to limit the speed of the support during the time the piston is connected to the support, and that when the movement of the support is reversed the piston will be automatically returned to its extended position in readiness for the next cycle of operation. Since the flow of fluid from the fuel reservoir to the cylinder ls relatively unrestricted, the piston is returned to its extended position at a rate muchV more rapid than the movement in the opposite direction When the exhaust of iluid fromthe cylinder is controlled by the adjustable valve.

We claim as our invention:

1. A device of the character described comprising an integrally formed casing open at the top having a circular recess at one end forming a cylinder and a recess at the other end forming a fluidy reservoir, a detachable cover plate for the top of said casing having an opening positioned above said cylinder, a piston in said cylinder having a portion extending out through said opening, a pair of coiled springs positioned intermediate the piston and the bottom of said cylinder for returning the piston to its extended position, a passage formed in said casing communicating at one end with said cylinder and extending under a portion of said reservoir, a supply port communicating at one end with said reservoir and at the other end with said passage, a ball check valve at one end of said supply port for preventing reverse flow of fiuid therethrough, an exhaust port communicating at one end with said passage and at its other end with said reservoir, a ring having a cylindrical bore forming a portion of-said exhaust port, a cylindrical valve member slidable in said bore and having a tapered groove therein, means for adjusting said valve member axially of said ring for varying the flow of iluid through said exhaust port, and means establishing communication between the upper end of said cylinder and the upper portion of said reservoir.

2. A device of the character described comprising an integrally formed casing open at the top having a circular recess forming a cylinder and a second recess forming a liuid reservoir, a detachable cover plate for the top of said casing having an opening positioned above said cylinder, a piston in said cylinder having a portion extending out through said opening, means for returning the piston to its extended position, a supply passage formed in said casing communicating at one end with said cylinder and at the other end with said reservoir, an exhaust port communicating at one end with said cylinder and at its other end with said reservoir, a ring having a cylindrical bore forming a portion of said exhaust port, a cylindrical valve member slidable in said bore and having a tapered groove therein, and means for adjusting said valve member axially of said ring for varying the ilow of iiuid through said exhaust port.

3. A device of the character described comprising an integrally formed casing open at the top having a. circular recess forming a cylinder and a second recess forming a fluid reservoir, a detachable cover plate for the top of said casing having an opening positioned above said cylinder., a piston in said cylinder having a portion extending out through said opening, a passage formed in said casing communicating at one end with said cylinder and extending under a portion of said reservoir, means for supplying fluid to said cyl- 'inder when the piston is moved to its extended position, an exhaust port communicating at one end with said cylinder and at its other end with said reservoir, and means for controlling the flow of fluid through said exhaust port.

4. A hydraulic governor comprising, in combination, a cylinder, a piston slidable in said cylinder and having a portion extending out through one end thereof, resilient means for moving the piston .to its extended position, means for limiting the outward movement of the pis'- ton and for preventing rotation thereof in the cylinder, a uid reservoir, a passage for conducting iiuid from said reservoir to the closed end of said cylinder embodying a check valve arranged to prevent reverse flow of iiuid therethrough, a passage communicating at one end with the closed end of the cylinder and at its other end with said reservoir for permitting exhaust of uid from said cylinder directly into said reservoir, a valve for controlling the flow of iluid through said exhaust passage, and means for adjusting said valve to determine the rate of ilow therethrough.

5. A hydraulic governor comprising, in combination, a cylinder having an opening in one end and a recess in the other end, a piston slidable in said cylinder and having a portion extending out through said opening, a coiled spring positioned in said recess and engaging said piston arranged to return the piston to its extended position, means for limiting the outward movement of the piston, a fluid reservoir, means for supplying uid to the closed end of said cylinder from said reservoir, an exhaust passage from the closed end of said cylinder leading directly to said reservoir, an adjustable valve for controlling the rate of ow through said exhaust passage, and means for adjusting said valve including an operating stem extending through said iiuid reservoir.

6. A hydraulic governor comprising, in combination, a cylinder, a piston slidable in said cylinder and having a portion extending out through one end thereof, resilient means for moving the piston to its extended position, a fluid reservoir, a passage for conducting fluid from said reservoir to the closed end of said cylinder embodying a check valve arranged to prevent reverse flow of fluid therethrough, a passage connecting the closed end of said cylinder with said reservoir, and means for controlling the 110W of uid through said last mentioned passage.

7. A hydraulic governor comprising, in combination, a cylinder having an opening in one end and a recess in the other end, a piston slidable in said cylinder and having a portion extending out through said opening, a coiled spring positioned in said recess and engaging said piston arranged to return the piston to its extended position, a fluid reservoir, means for supplying uid to the closed end of said cylinder, an exhaust passage from said cylinder leading directly to said supply means, and means for controlling the rate of flow through said exhaust passage when the piston is moved against the action of the spring.

8. A hydraulic governor comprising, in combination, a cylindrical member having a bore in one end thereof forming a cylinder, a piston slidably mounted in said cylinder, a. recess in said member communicating with the inner end of said cylinder, a coiled spring positioned in said recess and engaging said piston, means forming a fluid reservoir having a threaded portion extending laterally from the lower end thereof, a threaded opening in said member communicating with said recess in which said portion is positioned, a supply passage in said laterally extending portion communicating at one end with said reservoir and at the other end with said recess, a check valve in said supply passage, an exhaust passage in said laterally extending portion communicating at one end with said reservoir and at its other end with said recess, and an adjustable control valve for said exhaust passage.

9. A hydraulic governor comprising, in combination, a cylinder having an opening in one end thereof, a piston slidably mounted in said cylinder and having a portion extending out through said opening, resilient means for moving the piston to its extended position, a iluid reservoirI a supply passage intermediate the lower portion of said reservoir and the closed end of said cylinder embodying a check valve, an exhaust passage from the closed end of saidl cylinder to the lower portion of said reservoir, an adjustable valve for controlling the flow of fluid through said exhaust passage, and means establishing communication between the other end of said cylinder and the upper portion of said reservoir.

10. A hydraulic governor comprising, in combination, a cylindrical member having a bore in one end thereof forming a cylinder, a piston slidably mounted in said cylinder, a recess in said member communicating with the inner end of said cylinder, means forming a fluid reservoir having a threaded portion extending laterally from the lower end thereof, a threaded opening in said member communicating with said recess in which said portion is positioned, a supply passage in said laterally extending portion communicating at one end with said reservoir and at the other end with said recess, a check valve in said supply passage, an exhaust passage in said laterally extending portion communicating at one end with said reservoir and at its other end with said recess, and an adjustable control valve for said exhaust passage.

11. A hydraulic governor comprising, in combination, a cylinder having an opening in one end thereof, a piston slidably mounted in said cylinder and having a portion extending out through said opening, resilient means for mo'ving the piston to its extended position, a fluid reservoir, means for supplying a fluid to the closed end of said cylinder, an exhaust passage from the closed end of said cylinder to said reservoir, an adjustable valve for controlling the flow of fluid through said exhaust passage, and means for adjusting said valve including an operating member extending through said iiuid reservoir so that any fiuid leaking alongA the operating member passes into the reservoir.

12. A hydraulic governor comprising, in combination, a cylinder having an opening in one end thereof, a piston slidably mounted in said cylinder and having a portion extending out through said opening, resilient means for moving the piston to its extended position, a uid reservoir, means for supplying fluid to the closed end of said cylinder, adjustable valve means for controlling the exhaust of fluid from the closed end of said cylinder to the lower portion of said reservoir, an operating member Afor said valve means engageable externally of the governor, and means establishing communication between the interior of said reservoir and said operating member so that any fluid leaking along said member will be returned to the reservoir.

13. A hydraulic governor comprising, in combination, a vertically positioned cylinder, a piston slidable in said cylinder and having a portion extending out through the upper end thereof, rcoiled spring positioned in the recess in the lower end of the cylinder and engaging said piston arranged to return the piston to its extended position, means for limiting the outward movement of the piston, a fluid reservoir positioned directly into the reservoir, a. valve for controlling the flow of fluid through said exhaust passage, and means for adjusting said valve to determine the rate of 110W therethrough comprising a, stem extending through said reservoir.

LEO A. DUMSER. PAUL S. JACKSON. 

